1. Field of the Invention
The present disclosure relates to an organic electro-luminescence display device, and more particularly, to an organic electro-luminescence display device having charge transport patterns patterned by each sub-pixel unit.
2. Description of the Related Art
An organic electro-luminescence display device includes an anode, a cathode, and an organic light emission layer interposed between the two electrodes. The organic electro-luminescence display device realizes an image using the phenomenon that holes and electrodes provided from the anode and the cathode, respectively, recombine in the organic light emission layer to emit light. Therefore, since the organic electro-luminescence display device is a self-luminous device and because it does not need a backlight unit as in a liquid crystal display (LCD) device, it can be manufactured to have a slim profile and be lightweight. Also, since the organic electro-luminescence display device can be manufactured through a simple process, it is competitive in terms of price. Also, since the organic electro-luminescence display device has characteristics of low voltage driving, high emission efficiency, and a wide viewing angle, it rapidly emerges as a next generation display device.
The organic electro-luminescence display device further includes a hole transport layer (HTL) interposed between the anode and the organic emission layer, and an electron transport layer (ETL) between the cathode and the organic emission layer. Accordingly, holes and electrons are efficiently injected into the organic emission layer to improve light emission efficiency of the organic electro-luminescence display device.
The organic electro-luminescence display device includes a plurality of subpixels to display an image. Here, the subpixels include at least a red subpixel, a green subpixel, and a blue subpixel to realize full colors. The red, green, and blue subpixels should be disposed in portions of the organic emission layer that form red, green, and blue light, respectively. That is, a process for patterning the organic emission layer for respective red, green, and blue subpixels should be performed. Here, the HTL and the ETL are formed on the plurality of subpixels as a common layer for processing convenience. However, a current may leak to subpixels adjacent to each other due to the HTL and the ETL disposed on the plurality of subpixels. Such a leakage current generates cross-talk, which consequently, reduces image quality of the organic electro-luminescence display device.
To solve this limitation, the HTL and the ETL are patterned for each subpixel.
However, in the case where the patterning process is performed on the HTL and the ETL for each pixel, the number of processes increases, and thus manufacturing costs increase.
To solve this limitation, the organic emission layer, the HTL and the ETL can be patterned for each subpixel using a photolithography process requiring low-priced equipment compared to other patterning processes (for example, an inkjet printing process, and a deposition process using a shadow mask), and easy to perform. However, as the photolithography process is successively performed several times, the life of a device may be reduced. This is because the organic emission layer may be deteriorated by a solvent and a strip solution that removes a photoresist pattern while the HTL, the organic emission layer, and the ETL are patterned using the photolithography process.